There are billions of fluorescent light fixtures throughout the U.S. and the world. Most energy costs for lighting are generated in office and commercial space, which primarily utilize fluorescent light fixtures. It is estimated that commercial lighting demand consumes up to 25% of the total energy consumed in the U.S. alone. In addition, the Department of Energy (DOE) estimated in 2010 that linear fluorescent lighting represents the overall highest electricity consumer at 42 percent of energy used for lighting. With almost 15 billion square feet of office space in the U.S. alone this market is enormous. The DOE 2010 U.S. Lighting Market Characterization report estimates that 81.2 billion square feet in Commercial Building space that contains over 2.1 billion light fixtures in commercial buildings with 71.8% of commercial fixtures being linear fluorescent fixtures. This translates to more than 1.5 billion linear fluorescent fixtures in the U.S. in commercial buildings alone.
The commercial light fixture market has been predominantly standardized to 2×4 (2 foot×4 foot) recessed fixtures, which are typically installed in suspended grid ceiling systems. In addition to the overwhelming number of 2×4 fixtures there are also 2×2 and 1×4 fixtures and while most are recessed (or mounted on suspended grid ceiling systems)—some are surface mounted fixtures and still fewer are mounted in other ways. The change from fluorescent to LED that has already started is tantamount to when fluorescent lighting replaced incandescent lighting in commercial and industrial spaces.
Fluorescent fixtures have improved over the years for better efficiency and reduced energy consumption through the use of better ballasts and lamping modifications (T12, T8, T5, etc.). In addition various lens modifications have been designed over the years to reduce glare or improve light distribution, but they did not typically provide notable energy savings. Some fixtures and lamp types can be retrofitted with a dimming ballast—a key feature in reduction of energy consumption, however most fluorescent fixtures cannot be made dimmable. In more recent years dimming ballasts have been added to some fluorescent lamped fixtures—the most common commercial lamps deployed. However, these dimming ballasts are both expensive to purchase and install and they can dramatically reduce lamp life and ballast life, which increases the life cycle cost of the fixtures offsetting energy savings and reducing the incentive to upgrade the fixtures. The upgrades and modifications to fluorescent fixtures, lamps, ballasts and other components have largely been incentivized over the years with rebates, tax credits and other incentives which have covered much if not all of the costs for improvements to these fixtures to promote energy reduction. Likewise, numerous grants, rebates, and tax credits and other incentives are available to implement a retrofit from fluorescent to LED systems.
Commercial light fixtures typically function in banks or zones of lights within an office or commercial space and large numbers of lights may be ganged or interconnected and wired to one switch to reduce the number of switches, costs and complexity. Therefore, these light fixtures cannot be controlled individually or even effectively in smaller groups. A light switch or control system will govern specific banks of light fixtures or zones within an occupied space and these zones are highly inefficient in the use of energy for lighting since the controls apply to so many fixtures and lack flexibility. For example, an entire zone or bank of light fixtures on a given floor may be configured to illuminate the space for up to 50 employees or more. All these fixtures would typically be turned on during business hours and even after business hours, with every fixture consuming energy, even if only one or only a few employees were actually occupying various spaces within the larger illuminated zone. Even if occupancy sensors are applied to a given office or open office area as defined above—the sensor(s) typically control the same bank of lights controlled by the light switches which typically includes dozens of fixtures and not individual fixtures. Once again—the fluorescent systems do not typically dim so the entire field of lights is either on or off and not optimized. In certain applications, dual ballasts can be installed and dual switches for stepped dimming (e.g., either 50% or 100% dimming) can be used, however, such applications are generally not optimized.
There are also a number of inherent drawbacks in the current commercial light fixture offerings. The vast majority of these most common fluorescent lights contain fluorescent lamps, ballast and sockets with a housing (troffer) and a lens. For example, these fixtures contain hazardous materials—the fluorescent lamps contain mercury, which is highly toxic, and the vast majority of the original ballasts contained PCB—another very hazardous material. While many of these ballasts and/or fixtures have been replaced—many still exist in the field and as they age the odds of these units leaking PCB increases. Additionally, the light fixtures typically cannot be dimmed to reduce energy consumption. When fixtures are modified to accept dimmers they often reduce lamp and ballast life increasing life cycle costs—in addition to the cost of adding the dimmers. Even if dimmers are added they are typically not controlling individual fixtures, but rather large interconnected banks or groups of fixtures that must all be dimmed to the same levels regardless of illumination needs in smaller zones within the switched area. Many of these fixtures are ganged on switches so they cannot be individually controlled in large installations and are typically switched in large banks or zones requiring all the lights in a zone to be turned on—even if only one workspace is actually occupied. Where new technology has been applied to existing or new light fixture installations such as sensors and controllers they are installed in very limited ways to control fixtures in large banks within an installation but they do not provide for individual controls of a fixture within a large installation and none are configured and capable of working as a series of fixtures and components within a larger networked system to optimize every fixture. Existing retrofit kits for fluorescent fixtures generally require either a) labor intensive on-site assembly of all of the components needed for LED lighting systems inside an existing light fixture housing or troffer using double stick tape or clips and then re-use of the existing lens, which is not optimized for the new lamping; or b) another labor intensive effort in the replacement of existing components with some pre-assembled components (typically 3-6 components) that require field assembly of the components overhead; or c) the complete replacement of the existing light fixtures with new light fixtures which requires removal of all or most of the ceiling tiles, significant disruption to the occupants and function of the space, removal of the existing fixtures, installation of the new fixtures with multiple seismic ties from each new fixture to the structure above and clips for the new fixture to fasten it to the grid ceiling system as well and then re-installation of all the ceiling tiles and replacement of those damaged in the process. Additionally, often times existing lenses, which are typically re-used in these replacement efforts, are not optimized for the new light systems. Many existing lenses can be cracked, discolored, and inefficient and can reduce lighting performance by as much as 50%—diminishing the performance of the new retrofit assembly and the energy savings expected.